Thermal microplatform
AssigneeRoxburgh Ltd.
InventorWilliam N. Carr
Life of this patent
Estimating the term…
Abstract
A micromachined platform structure includes a substrate having a major surface and a platform positioned over the major surface. Plural support beams are tethered between the substrate and the platform, with each support beam including at least a first layer exhibiting a first thermal coefficient of expansion (TCE) and a second layer with a second TCE, the first TCE greater than the second TCE. The first layer is deposited on the second layer at a temperature that is higher than an ambient temperature at which the platform is to be used. Thus, at the ambient use temperature, the first layer is in a contraction/tension state relative to the second layer and causes a flexure of the support beams and an elevation of the platform away from the substrate's major surface.
Claims13
A micromachined platform structure comprising:
- a substrate having a major surface;
- a platform positioned away from said major surface;
- plural support beams tethered between said substrate and said platform, each said support beam comprising at least a first layer exhibiting a first thermal coefficient of expansion (TCE) and a second layer with a second TCE, said first TCE greater than said second TCE, said first layer deposited on said second layer at a temperature that is higher than an ambient temperature at which said platform is to be used, said first layer, at said ambient temperature, having contracted and in tension relative to said second layer, causing a flexure of said beam to elevate said platform to a static position away from said major surface.
A micromachined platform structure comprising:
- a substrate having a major surface;
- capacitive plate means formed on said substrate;
- a platform positioned away from said major surface and comprising plural layers exhibiting different thermal coefficients of expansion (TCEs), at least one of said layers comprising a conductive material, said platform responsive to applied heat to move with respect to said capacitive plate means on said substrate;
- plural support beams tethered between said substrate and said platform, each said support beam comprising at least a first layer exhibiting a first TCE and a second layer with a second TCE, said first TCE greater than said second TCE,
- said first layer deposited on said second layer at a temperature that is higher than an ambient temperature at which said platform is to be used, said first layer, at said ambient temperature, having contracted and in tension relative to said second layer, causing a flexure of said beam to elevate said platform away from said major surface;
- and
- means for sensing changes in capacitance between said capacitive plate means and said conductive material of said platform as an indication of a change of temperature of said platform.
A method for configuring a micromachined platform structure, said structure including a substrate having a major surface, a platform positioned upon a sacrificial material on said major surface and plural support beams tethered between said substrate and said platform, each support beam comprising at least a first layer exhibiting a first thermal coefficient of expansion (TCE) and a second layer with a second TCE, said first TCE greater than said second TCE, said method comprising the steps of:
- depositing said first layer on said second layer at a temperature that is higher than an ambient temperature at which said platform is to be used, said first layer thus being in tension at said ambient temperature;
- removing said sacrificial layer to enable, at said ambient temperature, said first layer to cause a flexure of said support beams to elevate said platform to a static position away from said major surface.
A method for configuring a micromachined platform structure that includes a substrate having a major surface, capacitive plate means formed on said substrate, a platform positioned on a sacrificial layer attached to said substrate, said platform comprising plural layers exhibiting different thermal coefficients of expansion (TCEs), at least one of said layers comprising a conductive material, said platform responsive to applied heat to move with respect to said capacitive plate means on said substrate, and plural support beams tethered between said substrate and said platform, each said support beam comprising at least a first layer exhibiting a first TCE and a second layer with a second TCE, said first TCE greater than said second TCE, said method comprising the steps of:
- depositing said first layer on said second layer at a temperature that is higher than an ambient temperature at which said platform is to be used, said first layer thus being in tension at said ambient temperature;
- removing said sacrificial layer to enable, at said ambient temperature, said first layer to cause a flexure of said support beams to elevate said platform to a static position away from said major surface;
- and
- sensing changes in capacitance between said capacitive plate means and said conductive material of said platform as an indication of a change of temperature of said platform.
Dependencies are inferred from the claim text.